The invention concerns a filter element for filtering a fluid as well as a filter system comprising a filter element, in particular an exchangeable oil filter of a motor vehicle.
Filter devices, in particular oil filters for internal combustion engines of motor vehicles, comprise usually a filter element by means of which a fluid flowing through the filter device is filtered. This filter element must be exchanged in regular intervals in order to be able to always ensure the filtration effect of the filter device. The filter element is removed together with removal of the filter device, for example, from an internal combustion engine. Due to the continuously growing environmental regulations, the exchange of the filter element must be possible in this context without the liquid, in particular oil, reaching the environment.
DE 10 2009 030 503 A1 describes such a removable filter device which enables an automatic opening or closing of a drainage channel when removing or installing a filter device so that the environment is not contaminated by draining oil upon exchange of the filter device. The filter device is screwed onto an internal combustion engine and is sealed by means of a flat O-ring seal.
For weight and cost reduction, such filters are produced increasingly of synthetic material. In this context, thermoplastic synthetic material and injection molding are convenient. The flow behavior of thermoplastic synthetic material even after hardening, i.e., during operation of the filter, makes it necessary that special constructive measures are taken in order to avoid seal tightness problems.
EP 0 930 928 B1 discloses a filter element in which this is achieved in that the seal, upon closing of a housing by a cover, absorbs axial as well as radial forces and thereby develops a sealing action in axial and radial direction. Due to the liquid pressure in the interior of the housing, the radial sealing action and the sealing behavior improve. Also, the cover is provided with a sealing groove in which the seal, which has no particular profile, is located. A projection with a slantedly extending end face is arranged on the housing. The slantedly extending end face is acting on the seal and generates thus the radial and axial sealing action.
The object of the invention is therefore to configure a filter element such that a reliable seal tightness of the filter element in operation, in particular after exchange of the filter element during servicing, is realizable.
A further object of the invention is to provide a filter system for receiving such an exchangeable filter element which realizes a reliable seal tightness of the filter element in operation, in particular after exchange of the filter element during servicing.